Liuet al.,Science 368 , 850–856 (2020) 22 May 2020 2of7
Fig. 2. Preparation and characterization of an A-CNT array.(AtoD)Schematic
images showing the process of preparing a wafer-scale A-CNT array. (E)Optical
image showing the dip-coating setup used for coating CNTs on a 4-inch silicon
wafer. (FtoH) SEM images showing an as-deposited CNT array obtained using an
optimal CNT solution concentration (40mg/ml) at different magnifications.
(I) Cross-section TEM image of a CNT array obtained using the highest CNT
solution concentration of 60mg/ml. The CNTs clearly show a density of at least
200 CNTs/mm (<5 nm pitch); even at this high CNT density, our CNT arrays still
present a good monolayer property, which is crucial for electronics applications.
(J) Diameter distribution of 200 CNTs measured by TEM. (K) Polarized Raman
spectra of CNTs for different incident anglesd. The polarization angle of the
incident light was changed through rotating al/2 wave plate during the
measurements, and the reference (zero angle) is not exactly parallel to the CNT
array. Inset: The Raman intensity is extracted and fitted in polar coordinates.
(L) Benchmarking of the degree of alignment as a function of CNT density. All data
used here are listed in table S2 ( 9 , 20 , 23 , 25 , 49 , 50 ).RESEARCH | RESEARCH ARTICLE